Revised 6.19.2017 by Rachel Micander Page 1
A Mineral is defined as an inorganic, naturally occurring, homogenous solid, with a definite chemical
composition, and ordered (crystalline) atomic structures.
Let’s break that definition down….
Inorganic: Involving neither organic life nor the products created from or by organic life.
Naturally Occurring: Must be formed by natural processes, meaning a mineral cannot be man-
made, manufactured, or created in a laboratory.
Homogeneous Solid: A mineral must be chemically and physically uniform down to the atomic level.
This homogeneity means that the mineral will have absolutely predictable physical properties
including hardness, density, and streak.
Definite Chemical Composition means that all occurrences of that mineral have a chemical
composition that varies within a specific limited range and the atoms that make up the mineral must
occur in specific ratios.
Ordered Atomic structure (Crystalline): The atoms in a mineral are arranged in a systematic and
repeating pattern. Glasses such as obsidian, which are disordered solids, liquids (e.g., water,
mercury), and gases (e.g., air) do not have a crystalline structure and are therefore not minerals.
Substance Mineral Why or Why Not?
Window glass no no regular internal structure
Amber
Coal
Diamond
Ice
Pearl
Pepper
Pyrite (Fools Gold)
____
Salt
Sugar
Water
